The present invention relates to security documents and, more particularly, to security documents including enhanced means for authenticating the security document.
Conventional security documents, e.g., the void pantograph security documents and the varying tone security documents of U.S. Pat. Nos. 4,579,370, 5,149,140, 5,197,765, 5,340,159, incorporate a security image designed to provide an indication of document authenticity on an attempted duplicate of the document. Often, the nature of the document authentication scheme is described in fine print along the top or bottom of the documentxe2x80x94xe2x80x9cCASH ONLY WHEN THE COLORED AREA OF THIS DOCUMENT CHANGES GRADUALLY AND EVENLY FROM DARKER TO LIGHTER WITH THE DARKER AREA AT THE TOPxe2x80x9d or xe2x80x9cTHE FACE OF THIS CHECK HAS A SECURITY VOID BACKGROUND PATTERNxe2x80x94DO NOT CASH IF VOID IS VISIBLE.xe2x80x9d Unfortunately, these printed messages are readily apparent and can be very useful to a potential counterfeiter. Further, these printed message do little to enhance the security of the document on which they are printed and are typically not well-suited for high speed machine authentication.
Accordingly, there is a need for a security document that eliminates the need for readily apparent printed descriptions of the authentication schemes embodied in a document. Further, there is continuing need for security documents incorporating enhanced security features that are well-suited for high speed machine authentication. Finally, there is a need for a device for authenticating such a document.
This need is met by the present invention wherein a security document and a device for authenticating the security document are provided. The device for authenticating the security document comprises an optical imaging device and a specially programmed controller. The security document comprises a unique combination of covert triggers, overt triggers, and overt secure document indicators arranged to enhance the security of the document at issue and enable high speed machine authentication of the document at issue.
In accordance with one embodiment of the present invention, a device for authenticating a security document is provided. The security document includes a security image printed on a face thereof. The security image is defined by a collection of security image elements and defines at least one document authentication scheme. The document authentication scheme is arranged to provide a primary indication of document authenticity. The authentication device comprises an optical imaging device and a specially programmed controller.
The optical imaging device is arranged to generate a security image signal representative of at least a portion of the security image. The controller is programmed to (i) define an authentication constellation within the security image, wherein the authentication constellation defines a set of constellation pixels, and wherein the constellation pixels are arranged at predetermined coordinates within the security image; (ii) identify respective occupation characteristics of each of the constellation pixels based on the security image signal, wherein each of the respective occupation characteristics represents a degree of printed matter within a selected constellation pixel; and (iii) determine whether the respective identified occupation characteristics correspond to an authentic document by comparing the respective identified occupation characteristics to a set of authentic occupation characteristics.
The security document may include a covert trigger defined by a set of covert trigger elements on the face of the security document and the controller may be programmed to identify the respective occupation characteristics based on printed matter defined by at least a portion of the covert trigger.
The controller may be programmed to identify the respective occupation characteristics based on printed matter defined by at least a portion of the security image. The security document preferably includes a covert trigger defined on the face of the security document and the controller is preferably programmed to identify the respective occupation characteristics based on printed matter defined by the covert trigger and the security image.
In accordance with another embodiment of the present invention, a device for authenticating a document is provided. The document includes an image printed on a face thereof. The image is defined by a collection of image elements. The authentication device comprises an optical imaging device and a specially programmed controller. The optical imaging device is arranged to generate an image signal representative of at least a portion of the image.
The controller is programmed to (i) define an authentication constellation within the image, wherein the authentication constellation defines a set of constellation pixels, and wherein the constellation pixels are arranged at predetermined coordinates within the image; (ii) identify respective occupation characteristics of each of the constellation pixels based on the image signal, wherein each of the respective occupation characteristics represents a degree of printed matter within a selected constellation pixel; and (iii) determine whether the respective identified occupation characteristics correspond to an authentic document by comparing the respective identified occupation characteristics to a set of authentic occupation characteristics.
In accordance with yet another embodiment of the present invention, a security document is provided comprising a security image and a covert trigger printed on a face of the document. The security image is defined by a collection of security image elements. The security image defines at least one document authentication scheme. The document authentication scheme is arranged to provide an indication of document authenticity. The covert trigger is defined by a collection of trigger elements. The trigger elements are arranged to resemble the security image elements so the covert trigger is not readily apparent on the face of the document. Preferably, the covert trigger elements and the security image elements are constructed of shapes having substantially identical geometry. The document authentication scheme may comprise a scheme selected from a void pantograph, an optically decodable security image, a varying tone security image, and combinations thereof.
The covert trigger may be arranged to provide an indication of document authenticity in addition to the indication of document authenticity provided by the document authentication scheme. If the security document includes at least one variable data field, the covert trigger may define an authentication parameter for the at least one data field. The variable data field may comprise a date field and the authentication parameter defined by the covert trigger may comprise an encoded date. Alternatively, the variable data field may comprise an amount field and the authentication parameter defined by the covert trigger may comprise a maximum amount limit.
The covert trigger may also be arranged to match a predetermined authentication mask or to identify the document authentication scheme.
The security document may further comprise an overt trigger arranged to be visually distinct from the security image elements. The overt trigger may also be arranged to provide an indication of document authenticity or to identify the document authentication scheme. Specifically, the overt trigger may include an encoded identification of the document authentication scheme. Alternatively, the overt trigger arrangement and the covert trigger arrangement may define substantially identical graphical images.
An overt secure document indicator may be arranged to be visually distinct from the security image elements and to provide a readily apparent indication that the document at issue includes enhances security features. The overt secure document indicator may comprise a graphical icon.
A security document according to the present invention may include a pseudo-covert trigger printed on the face of the document. The pseudo-covert trigger may be arranged as a decoy by printing it such that it is more apparent on the face of the document than the covert trigger and such that its elements are arranged to resemble the security image elements to a significantly lesser extent than the collection of trigger elements.
In accordance with yet another embodiment of the present invention, a method of authenticating a security document is provided. The security document at issue includes a security image printed on a face of the document. The security image includes a collection of security image elements and defines at least one document authentication scheme arranged to provide a primary indication of document authenticity. The method comprises the steps of: (i) defining an authentication constellation within the security image, wherein the authentication constellation defines a set of constellation pixels, and wherein the constellation pixels are arranged at predetermined coordinates within the security image; (ii) identifying respective occupation characteristics of each of the constellation pixels, wherein each of the respective occupation characteristics represents a degree of printed matter within a selected constellation pixel; and (iii) determining whether the respective identified occupation characteristics correspond to an authentic document by comparing the respective identified occupation characteristics to a set of authentic occupation characteristics.
A predetermined number of the authentic occupation characteristics may represent a degree of printed matter defined by a covert trigger defined on the face of the security document or by the security image itself. A predetermined number of the authentic occupation characteristics may represent an absence of printed matter within one of the selected constellation pixels. The step of identifying respective occupation characteristics of each of the constellation pixels may be executed by an automated machine.
In accordance with yet another embodiment of the present invention, a method of authenticating a document is provided. The document at issue includes an image printed on a face of the document. The image includes a collection of image elements. The method comprises the steps of: (i) defining an authentication constellation within the image, wherein the authentication constellation defines a set of constellation pixels, and wherein the constellation pixels are arranged at predetermined coordinates within the image; (ii) identifying respective occupation characteristics of each of the constellation pixels, wherein each of the respective occupation characteristics represents a degree of printed matter within a selected constellation pixel; and (iii) determining whether the respective identified occupation characteristics correspond to an authentic document by comparing the respective identified occupation characteristics to a set of authentic occupation characteristics.
In accordance with yet another embodiment of the present invention, a method of producing a security document is provided comprising the steps of: (i) defining a security image including a collection of security image elements, wherein the security image embodies a predetermined document authentication scheme arranged to provide an indication of document authenticity; (i) defining a covert trigger including a collection of trigger elements, wherein the trigger elements are arranged to resemble the security image elements; (ii) defining a trigger mask, wherein the trigger mask is arranged to define respective non-printed portions aligned with each of the trigger elements, and wherein each of the non-printed portions defines a non-printed buffer zone surrounding a corresponding trigger element; (iii) constructing a printed image from each of the security image, the covert trigger, and the trigger mask; and (iv) printing the constructed printed image on a substrate. The security image may include a background image layer, a message layer, a message layer mask, and a camouflage image layer.
Accordingly, it is an object of the present invention to provide an enhanced security document and security document authentication scheme that eliminates the need for printing readily apparent descriptions of a document""s security features on the document itself and satisfies the continuing need for security documents incorporating enhanced security features. Other objects of the present invention will be apparent in light of the description of the invention embodied herein.